Residential insulation: Preparing for Your Installation
Follow these guidelines for RESNET Grade 1 installation of fiberglass and rock and slag wool batt residential insulation.
Batt insulation materials
Fiberglass, rock and slag wool batts are common forms of residential insulation. They are available a variety of R-values, thicknesses and pre-cut widths and lengths. Batts are available plain (no facing), or with kraft paper facing or other types of vapor retarder facings. Tabless batts (also known as friction fit), that fit snugly in the wall cavity and stay in place without any fasteners until the wall finish is installed, are available with stapling flanges to hold them in place. Both tabless batts and the type with stapling flanges are acceptable for use in the ICC building codes and ASTM, ENERGY STAR and RESNET standards.
Preparation for proper installation of batt insulation
Before starting your batt insulation job:
- Make sure you have the right R-value to meet code or ENERGY STAR requirements
- Find out if vapor retarders are required
- Make sure you have the combination of products and associated tools needed to complete the job
For additional details, download Recommendations for Installing Insulation in Residential and Other Light-Frame Construction.
For R-value requirements, consult your local building code.
Perform a pre-insulation walk-through
Inspect all walls and ensure all cavities where insulation will be installed will have 6 sides after the wall finish is installed. That means there will be an exterior sheathing, such as insulation board or OSB, wood (or steel) studs on the four sides, and finally the wall finish on the interior. Because loose-fill or batt insulation on the attic floor and batts installed under floors are not exposed to significant air movement, they do not need to be covered on the exterior side. ENERGY STAR requires the installation of air baffles at the eaves to minimize the amount of air entering the edges of the insulation in the attics.
Make sure an effective air barrier system is in place
Minimizing air infiltration is dependent on the air barrier system and not the insulation type. The most important thing to do before installing fiberglass and rock wool batts in walls, and other parts of the building envelope, is to make sure there is an effective air barrier system in place.